(Editor’s note: This is an edited version of an article first published in the Washington Examiner on May 4, 2016 under the title, “Right-to-work strengthens workers.”)

By F. VINCENT VERNUCCIOand JASON HART

In March, the United Auto Workers reported that its membership grew 1.3 percent in 2015. This may come as a surprise to some because a substantial number of UAW members work in right-to-work states like Michigan. But the report highlights something worker-freedom supporters — and even some UAW officials — already knew: Right-to-work can be good for unions.

A recent report from the U.S. Bureau of Labor Statistics showed that in 2015, unions in what were then 25 right-to-work states gained more members than in states without the law. Membership increased by 125,000 in right-to-work states and only 91,000 in non-right-to-work-states and Washington D.C.

These gains come despite the fact that non-right-to-work states have over 7 million more workers than right-to-work states, according to the BLS report. The Illinois Policy Institute reports that this may be part of a long-term trend and not a one- or two-year fluke. Between 2005 and 2015, union membership grew in right-to-work states by about 1.3 percent, but fell around 9 percent in non-right-to-work states.

Six of the 10 states with the biggest increases in union membership were right-to-work. Overall, union membership increased in 16 of the nation’s 25 right-to-work states in 2015. In contrast, nine of the 16 states with shrinking membership still permit unions to collect involuntary dues or fees.

Even in states that have most recently enacted right-to-work, figures from the BLS sharply contrast with activists’ earlier warnings that unions would be devastated. For example, Michigan’s right-to-work law went into effect in early 2013 — and unions gained members that year. Membership did decline in 2014, but in 2015 unions in the state added 36,000 members. In nearby Indiana, union membership did fall last year, but there are still 37,000 more union members there than when right-to-work took effect in 2012.

So how does one explain this, especially considering that today’s unions are opposed to right-to-work laws? First, it’s important to remember that right-to-work laws do nothing to diminish a union’s ability to organize a workplace or a worker’s ability to become a union member and pay dues. If employees feel that they can achieve better wages, benefits and working conditions through a union, no right-to-work law will stand in the way of them signing up for one.

It may be that right-to-work actually makes unions stronger, because unions can no longer force all workers to financially support them. To win new members and keep current ones, unions in right-to-work states need to be more attentive and responsive to what workers care about most. In some ways, these unions face similar incentives to meet workers’ needs as any other business in the service industry does.

Some union officers even say right-to-work helps their recruitment efforts. Gary Casteel, now the UAW secretary-treasurer, said in 2014, when he was in charge of organizing Southern auto plants, “This is something I’ve never understood, that people think right-to-work hurts unions.”

“To me,” he continued, “it helps them. You don’t have to belong if you don’t want to. So if I go to an organizing drive, I can tell these workers, ‘If you don’t like this arrangement, you don’t have to belong.’ Versus, ‘If we get 50 percent of you, then all of you have to belong, whether you like to or not.’ I don’t even like the way that sounds, because it’s a voluntary system, and if you don’t think the system’s earning its keep, then you don’t have to pay.”

UAW President Dennis Williams has echoed these sentiments, telling the Detroit News, “I’ve always believed that if you do your job representing people, that people will be there to support you.”

Whether it’s by making the argument to organize new companies easier, as Casteel suggests, or simply because right-to-work states have faster job growth that leads to more opportunities for union jobs, unions are doing better in these states.

All these examples suggest that right-to-work can strengthen unions. It appears to do so by restoring unions’ incentive to earn dues the old fashioned way: by demonstrating their value to potential members, just as any other voluntary membership organization must do.

(F. Vincent Vernuccio is director of labor policy at the Mackinac Center for Public Policy, a research and educational institute headquartered in Midland. Hart is an Ohio-based reporter covering the Friedrichs Supreme Court case. His work has been featured at FoxNews.com, The Daily Signal, RedState, Washington Examiner, Townhall and elsewhere.)